2048 = generate & use up to 2048 bits(2048) = use up to 2048 bits, but not generate[2048] = encrypt up to 2048 bits, but not decrypt

X = full use, incl. new keys( x ) = use, but not on new keys

Note that RSAv3 keys do not include symmetric cipher
preferences. PGP defaults to IDEA when using RSAv3 keys.

X = full use, incl. new keys( x ) = use, but not on new keys

Note that PGP does not append message digest
algorithm preferences on the keys it creates. PGP defaults to MD5 for
RSAv3 keys and SHA1 for DH/DSS keys. For RSAv4 keys, PGP 7.0.x versions
use MD5, while the newer 7.1.x versions use SHA1.

X = full use, incl. new keys( x ) = use, but not on new keys

Note that PGP does not append compression algorithm
preferences on the keys it creates. PGP defaults to ZIP.

The 9x/Me, NT4, & Win2K columns give the max
size in gb of container volumes when those volumes are formated
FAT16/FAT32/NTFS respectively.

2048 = generate & use up to 2048 bits(2048) = use up to 2048 bits, but not generate[2048] = encrypt up to 2048 bits, but not decrypt

X = full use, incl. new keys( x ) = use, but not on new keys

Note that RSAv3 keys do not include symmetric cipher
preferences. PGP defaults to IDEA when using RSAv3 keys.

X = full use, incl. new keys( x ) = use, but not on new keys

Note that PGP does not append message digest
algorithm preferences on the keys it creates. PGP defaults to MD5 for
RSAv3 keys and SHA1 for DH/DSS keys. For RSAv4 keys, PGP 7.0.x versions
use MD5, while the newer 7.1.x versions use SHA1.

X = full use, incl. new keys( x ) = use, but not on new keys

Note that PGP does not append compression algorithm
preferences on the keys it creates. PGP defaults to ZIP.

The 9x/Me, NT4, & Win2K columns give the max
size in gb of container volumes when those volumes are formated
FAT16/FAT32/NTFS respectively.

2048 = generate & use up to 2048 bits(2048) = use up to 2048 bits, but not generate[2048] = encrypt up to 2048 bits, but not decrypt

X = full use, incl. new keys( x ) = use, but not on new keys

Note that RSAv3 keys do not include symmetric cipher
preferences. PGP defaults to IDEA when using RSAv3 keys.

X = full use, incl. new keys( x ) = use, but not on new keys

Note that PGP does not append message digest
algorithm preferences on the keys it creates. PGP defaults to MD5 for
RSAv3 keys and SHA1 for DH/DSS keys. For RSAv4 keys, PGP 7.0.x versions
use MD5, while the newer 7.1.x versions use SHA1.

X = full use, incl. new keys( x ) = use, but not on new keys

Note that PGP does not append compression algorithm
preferences on the keys it creates. PGP defaults to ZIP.

The 9x/Me, NT4, & Win2K columns give the max
size in gb of container volumes when those volumes are formated
FAT16/FAT32/NTFS respectively.

Note that the file system of the host drive will also
constrain the allowed max size of a PGPdisk volume. Generally speaking,
NTFS host drives will allow larger PGPdisk volumes. On PGP 6.5.x, FAT16/32 host
drives limit the max volume size to 2gb. For more detailed info on
PGPdisk Volume Sizes, see THIS page.

Note that PGPdisk from PGP 6.5.x builds will
automatically upgrade existing PGPdisk volumes from PGP 6.0.0 and
PGPdisk 1.0 to the newer PGPdisk format used by PGP 6.0.2 and 6.5.x.

2048 = generate & use up to 2048 bits(2048) = use up to 2048 bits, but not generate[2048] = encrypt up to 2048 bits, but not decrypt

X = full use, incl. new keys( x ) = use, but not on new keys

Note that RSAv3 keys do not include symmetric cipher
preferences. PGP defaults to IDEA when using RSAv3 keys.

X = full use, incl. new keys( x ) = use, but not on new keys

Note that PGP does not append message digest
algorithm preferences on the keys it creates. PGP defaults to MD5 for
RSAv3 keys and SHA1 for DH/DSS keys. For RSAv4 keys, PGP 7.0.x versions
use MD5, while the newer 7.1.x versions use SHA1.

X = full use, incl. new keys( x ) = use, but not on new keys

Note that PGP does not append compression algorithm
preferences on the keys it creates. PGP defaults to ZIP.

The 9x/Me, NT4, & Win2K columns give the max
size in gb of container volumes when those volumes are formated
FAT16/FAT32/NTFS respectively.

Note that the file system of the host drive will also
constrain the allowed max size of a PGPdisk volume. Generally speaking,
NTFS host drives will allow larger PGPdisk volumes. On PGP 6.0.x, FAT16/32 host
drives limit the max volume size to 2gb. For more detailed info on
PGPdisk Volume Sizes, see THIS page.

Note that PGPdisk from PGP 6.0.2 builds will
automatically upgrade existing PGPdisk volumes from PGP 6.0.0 and
PGPdisk 1.0 to the newer PGPdisk format used by PGP 6.0.2 (and 6.5.x).

2048 = generate & use up to 2048 bits(2048) = use up to 2048 bits, but not generate[2048] = encrypt up to 2048 bits, but not decrypt

* PGP 2.6.2 contains a bug that causes PGP to
generate 2047 bit RSAv3 keys even when 2048 bit keys (the max) are
requested. It can use true 2048 bit RSAv3 keys generated by other
versions of PGP.

X = full use, incl. new keys( x ) = use, but not on new keys

Note that RSAv3 keys do not include symmetric cipher
preferences. PGP defaults to IDEA when using RSAv3 keys.

X = full use, incl. new keys( x ) = use, but not on new keys

Note that PGP does not append message digest
algorithm preferences on the keys it creates. PGP defaults to MD5 for
RSAv3 keys and SHA1 for DH/DSS keys. For RSAv4 keys, PGP 7.0.x versions
use MD5, while the newer 7.1.x versions use SHA1.

X = full use, incl. new keys( x ) = use, but not on new keys

Note that PGP does not append compression algorithm
preferences on the keys it creates. PGP defaults to ZIP.

2048 = generate & use up to 2048 bits(2048) = use up to 2048 bits, but not generate[2048] = encrypt up to 2048 bits, but not decrypt

X = full use, incl. new keys( x ) = use, but not on new keys

Note that RSAv3 keys do not include symmetric cipher
preferences. PGP defaults to IDEA when using RSAv3 keys.

X = full use, incl. new keys( x ) = use, but not on new keys

Note that PGP does not append message digest
algorithm preferences on the keys it creates. PGP defaults to MD5 for
RSAv3 keys and SHA1 for DH/DSS keys. For RSAv4 keys, PGP 7.0.x versions
use MD5, while the newer 7.1.x versions use SHA1. Interestingly, the PGP
6.5.8ckt versions allow users to specify their own message digest
algorithm preferences (while official versions of PGP do not).

X = full use, incl. new keys( x ) = use, but not on new keys

Note that PGP does not append compression algorithm
preferences on the keys it creates. PGP defaults to ZIP.

The 9x/Me, NT4, & Win2K columns give the max
size in gb of container volumes when those volumes are formated
FAT16/FAT32/NTFS respectively.

Note that the file system of the host drive will also
constrain the allowed max size of a PGPdisk volume. Generally speaking,
NTFS host drives will allow larger PGPdisk volumes. On PGP
6.5.8ckt, FAT16/32 host
drives limit the max volume size to 4gb on WinNT4 & Win2K; on
Win9x/Me, FAT16/32 host drives limit volume size to 2gb. For more detailed info on PGPdisk
Volume Sizes, see THIS page.

2048 = generate & use up to 2048 bits(2048) = use up to 2048 bits, but not generate[2048] = encrypt up to 2048 bits, but not decrypt

* = includes RSAv3 key generation patch.

Note that while most versions of GPG will at least use
RSAv3 keys, the IDEA extension must be loaded in order for GPG to be
fully PGP 2.x compatible (PGP defaults to IDEA as the symmetric cipher
for RSAv3 keys, the only key type it uses). ** GPG 1.0.4 and earlier
will not load the IDEA extension, thus nixing PGP 2.x compatibility.

X = full use, incl. new keys( x ) = use, but not on new keys

* w/ IDEA extension

Note that RSAv3 keys do not include symmetric cipher
preferences.

X = full use, incl. new keys( x ) = use, but not on new keys

+ = with TIGER192 extension
# = with SHA2 extension

Note that RSAv3 keys do not include message
digest algorithm preferences.

X = full use, incl. new keys( x ) = use, but not on new keys

Note that RSAv3 keys do not include compression
algorithm preferences.

In addition to checking out many versions of PGP and GPG and consulting the accompanying documentation (e.g., ReadMe.txt, WhatsNew.txt, et al), I have also relied upon the following excellent sources for information on things PGP and GPG: